Finding the Fourth Proportional to 21,099.83, 31,634.01 and 12,778.02

Step by Step Solution

1. Step 1: Write the proportion equation
   21,099.83 : 31,634.01 = 12,778.02 : x
2. Step 2: Convert to fraction form
   21,099.83/31,634.01 = 12,778.02/x
3. Step 3: Cross multiply
   21,099.83x = 31,634.01 × 12,778.02
4. Step 4: Simplify right side
   21,099.83x = 404,220,012.46
5. Step 5: Solve for x
   x = 404,220,012.46/21,099.83
6. Step 6: Final answer
   x = 19,157.51